Matrix crimping tool



Oct. 13, 1964 F. J. LANG MATRIX CRIMPING Toor..

2 Sheets-Sheet l Filed March 14, 1962 j@ T AEM ZZ BY: @jm/V] Oct. 13, 1964 F. J. LANG MATRIX CRIMPING TooL 2 Sheets-Sheet 2 Filed March Y 14 1962 M/ T A@ a my United States Patent Oli ice 3,152,490 Patented 9ct. 13, 1954 3,152,4l MATREK CRE/@MG T0932 Franeis l. ilang, 1li/92 S. Hillcrest Drive, Lemon-t, lll. Filed Mar. 14, ldZ, Ser. No. 179,629 lil Claims. (Cl. .S2- 63) This invention relates generally to the art of dentistry, more particularly to dental matrices and expecially to devices for applying a ribbon-type dental matrix to a tooth using a crimpable locking element.

It is common practice to use a ribbon-type matrix as a mold in connection with the making or wax impressions for gold inlay work on teeth of the bicuspid or molar type. These matrices are also used for forming and hardening amalgam, porcelain and plastic fillings in cuspids and lateral and central incisors as well as in molar and bicuspid teeth. in accordance with conventional practice, such a matrix comprises a hat strip of thin ilexible spring steel of a width approximately equal to the height of a tooth and of a length approximating three inches. The strip is adapted to be wrapped around the tooth which is to be worked upon, and the ends of the strip are brought together by a specially formed matrix holder known as a retainer. According to former practice, the retainer was allowed to remain in the mouth of the patient in order to maintain tension in the matrix. However, more modern procedures call for use of a crimpable locking element known as a crimp lock; and once suitable tension has been drawn in the matrix, the crimp lock is pinched together using dental pliers to preserve the tension in the matrix, the crimp lock being positioned between the retainer and the tooth being worked upon prior to manipulation of the retainer to draw tension into the matrix. After the crimp lock has been pinched, the retainer is loosened and removed from the mouth of the patient prior to the performance of the actual Work on the tooth. The crimpable locking elements are ordinarily fashioned of an easily deformable material such as aluminum in order that they may be readily released from the matrix by simply pinching the locking element with a pliers away from the original point of pinching in order to open the element.

As will be recognized, the prior art schemes of applyin" a ribbon-type matrix to a tooth involves a considerable number of manipulations which must be performed with the month of the patient. The resultant time period during which appliances and the hands of the dentist must remain in the mouth oi the patient cause considerable fatigue and discomfort to the patient.

Therefore, an important object of the present invention is to provide means for quickly and eiliciently applying a ribbon-type dental matrix to a tooth.

A more general object of the invention is to provide a new and improved device for quickly and eiciently applying a ribbon-type dental matrix to a tooth.

Another object of the invention is to provide a device for applying a ribbon-type dental matrix to a tooth with a high degree of comfort to the patient.

Still another object of the invention is to provide a device for applying a ribbon-type dental matrix to a tooth with a minimum number of operations for performance within the mouth of the patient.

And et another object of the invention is to provide a hand tool for applying a ribbon-type dental matrix to a tooth.

A further object of the invention is to provide a hand tool of the type described which can be manipulated with one hand.

A still further object of the invention is to provide a hand tool of the type described which automatically holds a crimp-able locking element in position while the matrix is being tted loosely over a tooth.

And a still further object of the invention is to provide a hand tool of the type described which is arranged for one simple manipulation of the tool to tension the matrix and subsequently crimp the locking device about the ends of the tensioned matrix.

And a still further object of the invention is to provide a hand tool of the type described which is so constructed that release of manual force on the handles of the tool automatically releases both the matrix and the locking element.

These and other objects and features of the invention will become more apparent upon a reading of the following descriptions.

A device in accord with the invention includes a rst jaw member having a tip portion; a second jaw member slidably coupled to the first jaw member and having a tip portion confronting the tip portion of the first jaw member for grasping a crimpable locking member therebetween; independently movable means on one of the jaw members for drawing tension in a ribbon-type dental matrix which has been looped to permit opposite end portions thereof to be threaded between opposed portions of a locking element grasped by the tip portions of the jaw members; and handle means connected to the jaw members and to the independently movable means, the handle means being operative to actuate the movable means for tensioning the matrix and being operative subsequently to slide the second jaw member relative to the first jaw member whereby to converge the tip portions and apply a compressive force to the locking element for crimping the locking element about the tensioned matrix.

The invention, both to its structure and its mode of usage, will be better understood by reference to the following disclosure and drawings forming a part thereof, wherein:

FIG. l is a perspective view of a hand tool constructed in accordance with the principles of the invention, being shown immediately prior to the fitting of a ribbon-type dental matrix to a tooth, and a second position of one of the handle elements being shown in broken outline;

FlG. 2 is a side elevational view taken in central crosssection and showing the hand tool of the invention in its relaxed position;

FIG. 3 is a View similar to the showing of FIG. 2 but illustrating the invention in position for drawing tension into a ribbon-type matrix;

FIG. 4 is a view similar to the showing of FIG. 3 but illustrating the device in position for crimping a locking element in place about a tensioned matrix;

PIG. 5 is an enlarged perspective view of a crirnpable locking element for use with the hand tool of the invention;

FIG. 6 is an enlarged plan view in cross-section showing the hand tool of the invention holding a locking element and a dental matrix, the matrix being looped about a tooth and the hand tool being illustrated in its position immediately prior to actuation to draw tension into the matrix;

FIG. 7 is a view similar to the showing of FIG. 6 but illustrating the position of the hand tool of the invention after tension has been drawn into the matrix and after the locking element has been crimped about the matrix;

FIG. 8 is a view taken along the section 8*8 of FIG. 6;

FIG. 9 is an enlarged, fragmentary, exploded perspective view of the tip portions of the jaw members incorporated in the hand tool of the invention;

FIG. 10 is an enlarged, perspective view of the tip portion of the iixed jaw member viewed in a different aspect from that of FIG. 9;

FIG. l1 is an enlarged, perspective view of one component of the independent movable member used in drawing tension into the matrix; and

FIG. 12 is an enlarged, perspective view of another component of the independently movable means, shown with a coupling element used in connecting the independently movable means to one of the handle elements of the hand tool of the invention.

Referring now in detail to the drawings, specifically to FIG. 1, a pliers 20 constructed in accordance with the inventon is seen being used in applying a ribbon-type dental matrix 22 to a tooth 24 employing a crimpable locking element 26. In compliance with the present invention, the pliers 20 includes a fixed jaw 28, a slidable jaw 30 and a handleV arrangement 32. The pliers 20 also includes an independently movable arrangement which will be described With reference to subsequent figures of the drawlugs.

The dental matrix 22 and the locking element 26 are conventional elements and comprise no part of the present invention. However, in order that the invention may be readily understood, it is important to realize that the dental matrix 22 comprises a thin band of a suitable metal such as stainless steel, customarily taking a thickness of approximately 0.0015 inch. Similarly, the crimpable locking element 26 comprises a substantially V-shaped body of a readily deformable metal such as aluminum; and with reference to FIG. 5, the locking element 26 will be seen `to comprise a locking plate 34, a confronting locking plate 36 and an interconnecting bight 3S. The plates 34 and 36 include intertitting formations 49 and 42 respectively, and these interlitting formations provide a crimping type locking action on a dental matrix threaded between the plates 34 and 36 in the conventional manner to which reference will be had hereinafter. The plates 34 and 35 of the crimpable locking element are also fashioned with protruding lugs 44 and 45 respectively; and these lugs are positioned at the free ends of the plates 34 and 36 for use in grasping the locking element and holding it in a positive position.

Returning to FIG. 1, the fixed jaw 28 will be seen to include a relatively long, narrow nose portion 48 which terminates in a tip portion Si). The slidable jaw 39 is fashioned with a formed over tip portion 52 which confronts the tip portion 50 in order that a locking element 26 may be grasped therebetween. The nose portion 48 of the fixed jaw is narrow and elongated in order that the matrix 22 ca n be applied with facility in either lingual or labial preparation of a tooth.

With reference to FIG. 9, the slidable relationship between jaws 28 and 30 is seen to be established by the provision of interfitting means 54 which are directed to act between the jaw members. Specifically, the jaw 30 is fashioned with a male element 56 including longitudinally spaced pads 58 and 60 mounted on a rib 62. In addition, jaw 28 is fashioned with a longitudinally extending groove or female element 64 of inverted, T-shaped cross-section for receiving and retaining the male element 56. The groove 64 is provided with a centrally disposed enlargement 66 which is adapted to receive and pass the pad 60 into the floor of the groove.

In assembly of the jaws 28 and 30, the jaw 30 is positioned relative to the jaw 28 with the pad SS extending beyond the tip 50. Thereafter, the pad 6i) is lowered through the enlargement 66 until the pads 58 and 60 are aligned with the transverse portion of the groove 64 and the rib 62 has mateably engaged the upright portion of the groove. Next, the jaws are urged together to converge the tip portions 50 and S2 whereupon pad 60 moves out of alignment with enlargement 66 thereby positively positioning the jaws 28 and 30 with respect to each other while` permitting slidable movement of the jaw 30 relative to the jaw 28.

In accordance with the invention, the tip portions t) and 52 are contoured to receive iittingly different portions of a locking element 26 whereby releasably to retain the locking element in position relative to the jaws 28 and 30. Therefore and with continued reference to FIG. 9, the confronting surfaces of tip portions 50 and 52 will be seen fashioned with opposed pairs of transversely spaced recesses 68 and 7i) respectively. The recesses e8 are adapted to receive the lugs 44 of locking element 26 and recesses 70 are adapted to receive the lugs 46 of the locking element in fitting engagement in order that a locking element 26 can be situated in the jaws 28 and 30 with assurance that the locking element will remain in place without special attention.

T he pliers 20 have been described hereinabove as comprising an independently movable arrangement as a major component or sub-assembly; and it is important at this juncture to indicate that the independently movable arrangement is employed in drawing tension in a dental matrix which has been looped to permit opposite end portions thereof to be threaded between the plates 34 and 35 of a locking element 26 which is grasped between the tip portions 50 and 52 of the jaws 28 and 30. Considering FIG. 2, the xed jaw 28 will be seen fashioned with a longitudinal recess 72; and an independently movable arrangement 74 will be seen received in the recess 72. Turning to FG. 6, the arrangement 74 includes a U-shaped, forwardly disposed member 75 and a rearwardly disposed member 78 fashioned in the shape of an open, rectangular box. The members 76 and 7S are appropriately coupled to move in unison; and for purposes of coupling the members 76 and '78, the member '78 is provided at its forward end with a hook-like formation 80 as is well shown in FIG. 12. With reference to FIG. 11, the U-shaped member '76 is seen comprised of arms 82 and 84 and an interconnecting bight portion 86; and one edge of the bight portion 85 is fashioned with a notch 88 congurated to accommodate the inected portion of formation 80 in the coupling of the members 76 and 78.

The arms 82 and 84 of U-shaped member 76 are disposed in opposed relationship in order to grasp the opposite end portions of a dental matrix therebetween. Therefore, the member 76 is fabricated from a suitable spring material in order that the arms 82 and 84 may be resiliently convergible. Furthermore, cam means are provided to act between the walls of recess 72 and the arms 82 and 84 to converge the arms upon relative sliding movement between the arrangement 74 and the jaw 28 in which it operates. Specifically, the recess 72 is fashioned with laterally opposed recesses 9@ and 92, best shown in FIG. 7. The recesses and 92 define cam surfaces which coact with cam followers defined by lateral protuberances 94 and 96 provided respectively on the arms 82 and 84 adjacent the ends thereof. With reference to FIG. 11, the arms 82 and 84 will be seen fashioned with a V-shaped groove 98 and a cooperatively shaped tongue 100 which are juxtaposed with the protuberances 96 and 94 respectively. As will be realized, upon a converging of the arms 82 and 84, the tongue 100 will iittingly enter the groove 98 to crimp and grasp the ends of a dental matrix situated therebetween.

In accordance with a feature of the invention, the arrangement 74 is intended to be biased so as normally to take a position in which the protuberances 94 and 96 reside in the recesses 90 and 92 as is shown in FIG. 6; and for this purpose,.counterbalancing compression springs 102 and 164 are included in the arrangement '74. As is well shown in FIG. 12, a bore 106 is fashioned in the rear end of member7; and a shaft i0?, is slidably passed through bore 1% to receive thereabout the spring 102 and the spring 104, spring 102 being disposed within the confines of member '78 and spring 104 being disposed rearwardly of that member. A head is formed on shaft 108 at the end thereof which is found within the member 78 in order to confine spring 102 against the rear end of the member 78. Similarly, recess 72 is fashioned with a shoulder 112 which confronts 5 the end of spring 104, as is shown in FIG. 2, to coniine the spring 104 against the member 78.

Continuing with reference to FIG. 2, the handle arrangement 32 will be seen to include a handle element 114 rigidly connected to the fixed jaw 23, a movable handle element 115 swingably mounted to handle element 114 by a pivot pin 118, and coupling units 12d and 122 respectively connecting the slidable jaw 33 and the arrangement 74 to the swingable handle element 116. The coupling unit 12% includes a bracket 124 (also shown in FIG. 9) extending from rib 62 of the slidable jaw 30. The coupling unit 121i also includes a bolt element 126 which threadedly engages bracket 124 at one end and which passes freely through apertures 12S and 13%) formed respectively in rigid handle element 114 and swingable handle element 116. The handle element 116 is also fashioned with a pocket 132 which opens into the aperture 130; and bolt element 126 is provided with a head 134 at its free end, head 134 being adapted to coact with the door of pocket 132 in a manner to be described hereinafter.

ln order that the arrangement 74 may be actuated prior to the actuation jaw Sti, the coupling unit 122 is disposed at a greater radial distance from the center of pivot pin 11S than the coupling unit 12?. ln addition, coupling unit 122 includes aligned apertures 136 and 133 fashioned respectively in ixed jaw 221 and the swingable handle element 116, handle element 116 being additionally provided vrith a pocket 14? which opens into aperture 13S. The shaft 133 is employed as a retainer for the springs 102 and 134 and includes a portion which extends through the apertures 136 and 138 to have an enlargement 142 (also shown in FIG. l2) formed on the end thereof which is disposed in pocket 14%.

Head 134 cooperates with pocket 132 and enlargement 142 cooperates with pocket 14@ in developing a ball joint action in the coupling units 129 and 122. Furthermore, the thickened portions defined respectively by head 134 and enlargement 142 control or limit the slidable movement of bolt element 126 arid shaft 198 through the sets of apertures 12S, 136 and 13e, 138.

As has been described, the convergi'ole arms S2 and 84 of arrangement 74 are intended to grasp therebetween opposite end portions of a ribbon-type dental matrix, the intermediate portions of which are disposed between the plates 34 and 36 of a crimpable locking element 26. To facilitate passage of the end portions of the matrix from the locking element to the convergible arms S2 and S4, the tip portion Si) of ixed jaw 28 is fashioned with confluent slots 144 and 146 as is shown in FIG. l0, slots 144 and 146 each having a width suliicient to pass a double thickness of the matrix material in a slidable manner. The confluence of slots 144 and 146 opens into recess 72; and as is shown in FIG. l0, the end portion of recess 72 which receives the slots 144 and 146 is exposed to permit manual manipulation of opposite end portions of a dental matrix into proper position between the arms 82 and S4 when they are disposed in their relaxed com'iguration. As will also be seen from an inspection of FIG. l0, the remainder of recess 72 is closed by a plate 14S after the components of the arrangement 74 have been assembled within the recess. Comparing FIGS. 2 and ll, it Will be noted that arms 82 and S4 are provided with perpendicularly extending end portions 159 which are adapted to operate in the portion of recess '72 which is exposed between plate 148 and the confluence of slots 144 and 146.

Having thus described one construction of the invention, it is important now to state how the illustrated embodhnent operates.

FIGS. 2, 3 and 4 illustrate operation of the handle arrangement 32 to affect actuation of the independently movable arrangement 74 and subsequent actuation of slidable jaw 31). FIG. 2 shows the relaxed condition of the pliers 20; and there, the tip portion 52 will be seen spaced from the tip portion Sli for reception of a locking element 126. Moreover, the arrangement 74 will be seen disposed in its normal or matrix-releasing condition established by the counterbalancing springs 102 and 104.

1n FIG. 3, the swingable handle element 116 wl be seen to have been moved toward rigid handle element 114, i.e. moved in the direction indicated by arrow 152. Swinging of the handle element 116 to the extent illustrated in FlG. 3 will cause the floor of pocket 140 to engage and apply force to the enlargement 142 which is formed on shaft 108. This force will cause shaft 10S to move in the direction indicated generally by arrow 154; and this movement will be recognized by a compression of springs 1112 and 104 and a movement of the arrangement 74 in the direction of arrow 154. The rearward sliding movement of the arrangement 74 will result in the cam followers defined by protuberances 94 and 95 being transported out of the recesses 90 and 92, i.e. from the condition shown in FlG. 6 to the condition shown in FIG. 7. A converging of the arms 82 and 84 will result whereby to clamp the end portions of a dental matrix disposed between the groove 9S and the tongue 1b@ and whereby to draw tension into the dental matrix.

Continued pivoting of handle element 116 in the direction of arrow 152 will cause the floor of recess 132 to engage the head 134 of bolt element 126 whereupon additional converging movement between the handle elements 114 and 115 will result in a relocation of bolt element 126 in a general rearward direction indicated by arrow 154. Because bolt element 126 is connected to slidable jaw 30 through the bracket 124, this movement of the bolt element will cause a corresponding movement of the jaw StB whereby to converge the tip portions 5t) and 52 for crimpable operation on a locking element disposed therebetween. This latter condition of the pliers 2G is illustrated in FlG. 4.

A relaxation of the manual gripping of handle elements 11d and 116 will release the handle arrangement 32 to the action of springs 1112 and 194; and the energy stored in the springs by converging of the handle elements will return the pliers 2i) to its original or relaxed condition shown in FIG. 2.

In use, a crimpable locking element 2e will be fitted between the tip portions Si? and 52 of jaws 28 and 39 as is shown in FIG. 6; and thereafter, a dental matrix 22 will be bent in the form of a loop, intermediate portions of the matrix 22 being disposed between the plates 34 and 36 of the locking element as is also shown in FIG. 6. Next, the opposite end portions of the matrix 22 will be threaded through either slot 144 or slot 145 according to the side of the pliers 2@ from which it is intended to have the matrix 22 extend. When the end portions of the matrix 22 have been passed through one of the slots 144 and 14d, the trailing parts of these end portions will be manually disposed between the convergible arms 82 and 84. The pliers 2l? will thus be readied for actual use.

To install the matrix 22 in place about a tooth 24 having, for example, a portion 15e excavated to remove a caries, it is only necessary to insert the tip portions ot the pliers quickly into the mouth of the patient and slip the matrix 22 loosely about the tooth 24 as is shown in FlG. 6. Thereafter, a simple squeezing of the handle elements 114 and 116 into converging relationship will iirst draw tension into the dental matrix to fit it tightly about the tooth 24 and thereafter will converge the plates 34 and 36 of the locking element to crimp the locking element and preserve the tension drawn in the matrix 22. Release of the handle element 116 results in the tip portions 5i? and 52 returning to their normal, spaced condition under the influence of the springs 102 and 1%4; and when but one side of the locking element 26 is held in the contoured ends of one of the tip portions, only the slightest twisting of the pliers relative to the tooth will dislodge the locking element from the tip portion of the pliers. The pliers may then be withdrawn from the mouth of the patient. As will be recognized, the pliers 20 achieves -a quick and efficient application of the matrix 22 with a resultant high degree of comfort to the patient.

The specific example herein shown and described is t0 be considered as being primarily illustrative. Various changes in structure will, no doubt, occur to those skilled in the art; and these changes are to be understood as forming a part of this invention insofar as they fall within the spirit and scope of the appended claims.

The invention is claimed as follows:

1. A pliers for applying a ribbon-type dental matrix to a tooth using a crimpable locking element, said pliers comprising: a first jaw member having a relatively long nose portion terminating in a tip portion; a second jaw member having a tip portion disposed confronting the tip portion of said rst jaw member for grasping a said locking member therebetween; interfitting means acting between said jaw members slidably to couple said members, including a male element on one jaw member and a cooperating female element on the other jaw member; independently movable means on said first jaw member for drawing tension in a said dental matrix which has been looped to permit opposite end portions thereof to be threaded between opposed portions of a said locking element grasped by said tip portions; and handle means connected to said jaw members and -to said independently movable means, said handle means being operative to aetuate said independently movable means for tensioning said matrix and being operative subsequently to slide said second jaw member relative to said fast jaw member whereby to converge said tip portions and apply a compressive force to said locking element for crimping said locking element about said tensioned matrix.

2. A pliers for applying a ribbon-type dental matrix to a tooth using a crimpable locking element, said pliers comprising: a tirst jaw member having a relatively long nose portion terminating in a tip portion, said iirst jaw member including means delining a longitudinally extending groove of element-retaining cross-section; a second jaw member slidably coupled to said first jaw member and having a tip portion confronting the tip portion of said first jaw member for grasping a said locking member therebetween, said second jaw member including a formation slidably and mateably receivable in said groove; independently movable means on said first jaw member for drawing tension in a said dental matrix which has been looped to permit opposite end portions thereof to be threaded between opposed portions of a said locking element grasped by said tip portions; and handle means connected to said jaw members and to said independently movable means, said handle means being operative to actuate said independently movable means for tensioning said matrix and being operative subsequently to slide said second jaw member relative to said first jaw member whereby to converge said tip portions and apply compressive force to said locking element for crimping said element about said tensioned matrix.

3. A pliers for applying a ribbon-type dental matrix to a tooth using a crimpable locking element, said pliers comprising: a first jaw member having a relatively long nose portion terminating in a tip portion and having means defining a longitudinal recess; a second jaw member movable relative to said iirst jaw member and having a tip portion confronting `the tip portion of said first jaw member for grasping a said locking member therebetween; independently movable means received in said recess, including opposed and slidable arms adapted to grasp the opposite end portions of a said dental matrix which has been looped to permit opposite end portions thereof to be threaded between opposed portions of a said locking element grasped by said tip portions, movement of said arms relative to said first jaw member being adapted to draw tension in said matrix; and handle means connected to said jaw members and to said independently movable means, said handle means being operative to actuate said independently movable means for tensioning said matrix and being operative subsequently to move said second jaw member relative to said first jaw member whereby to converge said tip portions and apply a compressive force to said locking element for crimping said element about said tensioned matrix.

4. A pliers according to claim 3 and further comprising cam means acting between the walls of said recess and the surfaces of said arms confronting said walls for converging said arms upon relative 'movement between said movable means and said rst jaw member.

5. A pliers for applying a ribbon-type dental matrix to a tooth using a crimpable locking element, said pliers comprising: a first jaw member having a relatively long nose portion terminating in a tip portion and having means dening a longitudinal recess; a second jaw member slidably 'coupled to said first jaw member and having a tip portion confronting the tip portion of said first jaw member for grasping a said locking member therebetween; independently movable means slidably received in said recess, including opposed and slidable arms adapted to grasp the opposite end portions of a said matrix therebetween, sliding of said movable means relative to said first jaw member causing tension to be drawn in a said dental matrix which has been looped to permit opposite end portions thereof to be threaded between opposed portions of the said locking element grasped by said tip portion; counterbalancing spring means operating between said independently movable means and said rst jaw member normally to position said movable means in matrix-releasing condition; and handle means including a first handle element rigid with said first jaw means, a second handle element pivotally mounted to said iirst handle element, and coupling means connecting said second jaw member and said movable means to said second handle element so constructed and arranged that pivoting of said handle elements .into converging relationship slidably transports said movable means for tensioning said matrix and for subsequently converging said tip portions and applying a compressive force to said locking element for crimping said locking element about said tensioned matrix.

6. A pliers for applying a ribbon-type dental matrix to a tooth using a crimpable locking element, said pliers comprising: a first jaw member having a relatively long nose portion terminating in a tip portion and having means deiining a longitudinal recess; a second jaw member movable relative to said first jaw member and having a tip portion confronting the tip portion of said rst jaw member for grasping a said locking member therebetween; independently movable means received in said recess, including opposed and slidable arms adapted to grasp the opposite end portions of the said matrix therebetween,v

relative movement of said movable means causing tension to be drawn in a said dental matrix which has been looped to permit opposite end portions thereof to be threaded between opposed portions of the said locking element grasped by said tip portions; and handle means including a first handle element rigid with said iirst jaw means, a second handle element pivotally mounted to said first handle element, and coupling means connecting said second jaw member and said movable means to said second handle element respectively at a lesser and a greater radial distance from the center of the pivot of the said second handle element whereby pivoting of said handle elements into converging relationship actuates said movable means for tensioning said dental matrix and moves said second jaw member relative to said first jaw member for converging said tip portions and applying a compressive forceV to said locking element thereby crimping said element about said tensioned matrix.

7. A pliers for applying a ribbon-type dental matrix to a tooth using a crimpable locking element, Said pliers comprising: a iirst jaw member having a relatively long nose portion terminating in a tip portion, said rst jaw member including means deining a longitudinally extending groove of element-retaining cross-section, said jaw member further having means defining a longitudinal recess disposed parallel with said groove; a second jaw member slidably coupled to said tirst jaw member and having a tip portion confronting the tip portion of said rst jaw member for grasping a said locking member therebetween, said second jaw member including a formation slidably and mateably receivable in said groove; independently movable means slidably received in said recess, including opposed, resiliently convergible and slidable arms adapted to grasp the opposite end portions of a said matrix therebetween, sliding of said movable means causing tension to be drawn in a said dental matrix which has been looped to permit opposite end portions thereof to be threaded between opposed portions of the said locking element grasped by said tip portions; and handle means connected to said jaw members and to said independently movable means, said handle means being operative to actuate said independently movable means for tensioning said matrix and being operative to slide said second jaw member relative to said rst jaw member whereby to converge said tip portions and apply a compressive force to said locking element for crimping said element about said tensioned matrix.

8. A pliers for applying a ribbon-type dental matrix to a tooth using a crimpable locking element, said pliers comprising: a rst jaw member having a relatively long nose portion terminating in a tip portion; a second jaw member slidably coupled to said rst jaw member and having a tip portion confronting the tip portion of said first jaw member for grasping a Said locking member therebetween; independently movable means on said rst jaw member for drawing tension in a said dental matrix which has been looped to permit opposite end portions thereof to be threaded between opposed portions of a said locking element grasped by said tip portions; and handle means including a rst handle element rigid with said rst jaw means, a second handle element pivotally mounted to said rst handle element, and coupling means individually connecting said second jaw member and said movable means to said second handle element respectively at a lesser and a greater radial distance 'om the center of the pivot of said second handle element whereby pivoting of said handle elements into converging relationship slidably transports said movable means for tensioning said matrix and slides said second jaw member relative to said rst jaw member for converging said tip portions and applying a compressive force to said locking element thereby crimping said element about said tensioned matrix.

9. A pliers for applying a ribbon-type dental matrix to a tooth using a crimpable locking element, said pliers Comprising: a i'lrst jaw member having a tip portion and a handle element rigid with and extending from said tip portion; a second jaw member movable relative to said first jaw member and having a tip portion confronting the tip portion of said rst jaw member for grasping a said locking element therebetween; independently movable means on one of said jaw members for use in drawing tension in a said matrix which has been looped to permit opposite end portions thereof to be threaded between opposed portions of the said locking element grasped by said tip portions, including means connectable to end portions of said matrix; and handle means including a second handle element mounted for movement relative to said rst jaw member and aligned With said first mentioned handle element to be grasped therewith, said handle means further including coupling means connected to said second handle element for movement in response to movement thereof, said coupling means connecting said handle element to said second jaw member and to said independently movable means for actuation of said independently movable means to tension said matrix in advance of actuation of said jaw members to converge the tip portions thereof and apply a compressive force to the said locking element for crimping said element yabout said tensioned matrix.

10. A pliers according to claim 9 wherein the tip portions Of said jaw members are contoured ttingly to receive different portions of a said locking element Whereby releasably to retain said locking element in position relative to said jaw members.

References Cited in the le of this patent UNITED STATES PATENTS 713,041 Townsend Nov. 4, 1902 2,082,669 Voigt June 1, 1937 2,588,059 Toiemire Mar. 4, 1952 2,608,893 Cranner Sept. 2, 1952 2,769,238 McPhee Nov. 6, 1956 2,853,782 Gruenwald Sept. 30, 1958 

1. A PLIERS FOR APPLYING A RIBBON-TYPE DENTAL MATRIX TO A TOOTH USING A CRIMPABLE LOCKING ELEMENT, SAID PLIERS COMPRISING: A FIRST JAW MEMBER HAVING A RELATIVELY LONG NOSE PORTION TERMINATING IN A TIP PORTION; A SECOND JAW MEMBER HAVING A TIP PORTION DISPOSED CONFRONTING THE TIP PORTION OF SAID FIRST JAW MEMBER FOR GRASPING A SAID LOCKING MEMBER THEREBETWEEN; INTERFITTING MEANS ACTING BETWEEN SAID JAW MEMBERS SLIDABLY TO COUPLE SAID MEMBERS, INCLUDING A MALE ELEMENT ON ONE JAW MEMBER AND A COOPERATING FEMALE ELEMENT ON THE OTHER JAW MEMBER; INDEPENDENTLY MOVABLE MEANS ON SAID FIRST JAW MEMBER FOR DRAWING TENSION IN A SAID DENTAL MATRIX WHICH HAS BEEN LOOPED TO PERMIT OPPOSITE END PORTIONS THEREOF TO BE THREADED BETWEEN OPPOSED PORTIONS OF A SAID LOCKING ELEMENT GRASPED BY SAID TIP PORTIONS; AND HANDLE MEANS 